body {  
    display: flex;  
    justify-content: center;  
    align-items: center;  
    height: 100vh;  
    background-color: #f5f5f5;  
}  
  
.canvas {  
    width: 300px;  
    height: 300px;  
    background-color: #ffffff;  
    border: 2px solid #000000;  
    position: relative;  
}